Coronary Heart Disease is a leading cause of disability and the leading cause of death among American women. Older women have lower levels of habitual physical activity and lower levels of physical functioning than older men, explained in part by lower strength and muscle mass. Older female coronary patients further curtail their activities due to apprehension regarding the safety of physical activities, further compounding their deconditioning. Resistance training as a therapeutic modality to increase physical activity and physical functioning in older female CHD patients has not been examined. The goals of this research program are to determine the effects of resistance training, delivered in a cardiac rehabilitation setting, on: free-living physical activity using doubly-labeled water, stable isotope methodology, physical functioning and body composition, measured by questionnaire, physical performance testing and dual x-ray absorptiometry. Collectively, these results will test the hypothesis that significant increases in muscle strength and muscle mass are important determinants of increased habitual physical activity and physical functioning in older, community dwelling, female coronary patients. Primary study outcomes will include stable isotope measures of total free-living physical activity, patient-described and investigator-observed measures of physical functioning, and measures of muscle strength and muscle mass. In summary, this study is intended to provide important data on a practical clinical intervention aimed at increasing physical activity and physical functioning in older female coronary patients with functional disability.